Systems and methods for real-time tracking of a target tissue using imaging before and during therapy delivery

ABSTRACT

Described herein are systems and methods for tracking a target tissue during therapy delivery. A system for identifying an anatomical structure and tracking the motion of the anatomical structure using imaging before and during delivery of a therapy to a patient includes an imaging module and a therapy module. In some cases, the imaging module is configured to identify a region of the anatomical structure in an image, and the therapy module is configured to deliver the therapy to a target tissue. A method for imaging during delivery of a therapy includes acquiring an image, identifying a region of an anatomical structure, tracking the region of the anatomical structure, integrating the tracking, generating a unique template library, determining if a pre-existing template matches the results or if the results should be updated as a new template, and delivering the therapy to the target tissue.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 62/075,487, filed on Nov. 5, 2014, pending, theentire disclosure of the above application is expressly incorporated byreference herein.

This application is related to international PCT patent applicationserial No. PCT/US2014/022141, titled “TRANSDUCERS, SYSTEMS, ANDMANUFACTURING TECHNIQUES FOR FOCUSED ULTRASOUND THERAPIES”, filed onMar. 7, 2014, which is herein incorporated by reference in its entirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference in their entirety, as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference in its entirety.

TECHNICAL FIELD

This invention relates generally to the imaging field, and morespecifically to a new and useful system and method for real-timetracking of a target tissue using imaging before and during therapydelivery.

BACKGROUND

Therapeutic energy delivery from a distance involves transmission ofenergy waves to affect a target tissue inside a patient's body.Therapeutic delivery of ultrasound waves has been used in a wide varietyof therapeutic interventions, including lithotripsy, drug delivery,cancer therapy, thrombolysis, and tissue ablation. Non-invasive deliveryof focused energy may allow for more efficient delivery of energy to thetarget tissue, improved cost effectiveness of treatment, minimizedtrauma to the patient's body, and improved recovery time.

Delivering energy over a distance requires targeting accuracy andtechnological flexibility while minimizing invasiveness into thepatient. However, current methods fail to adequately track the targettissue motion while concurrently delivering the energy or therapy. Atissue in the body moves relative to the energy-delivering source fromeither the unintended patient body motion or the internal organs' motiondue to heartbeat, breathing, blood flow, or other physiologicalfunctions. Current methods stop delivering the energy or therapy whenthe tissue moves out of focus or visibility due, at least, to breathingor shadows and reinitiates energy or therapy delivery when the tissuereemerges. The stopping and starting of therapy or energy delivery canhave unintended consequences for the patient, such as variable dosing,uneven or insufficient therapy delivery to the target tissue, andprolonged procedure times.

Conventional ultrasound systems for tracking a targeted soft tissuemotion have a much lower signal-to-noise ratio. Further, the shape of atarget image can change more as it moves within the image because ofultrasound beam scan orientation, tissue deformation, ultrasound signaldistortion and other factors. Controlling these factors is desirable foreffective and accurate therapeutic energy delivering to the targettissue. Since soft tissue deforms at a macroscopic level, conventionaltracking systems cannot adequately track such tissue deformation andmotion. Further, tracking and energy delivery will halt when aconventional system loses the target tissue, due to, for example, ribshadows or deep breaths that move the target out of sight. This happensregularly in conventional systems. Conventional systems are notconfigured to deal with these motions, and even more importantly theyare not configured to properly recover tracking once the imagereappears, requiring user input to relocate the lost target tissue inthe image.

Thus, there is a need for a new and useful system and method fortracking a target tissue using imaging before and during therapydelivery. In particular, there is a need for new and useful systems andmethods configured to accommodate when tissue moves out of focus orvisibility, and even more importantly configured to automaticallyrecover tracking when the image reappears. This invention provides sucha new and useful system and method.

SUMMARY

A system for identifying at least one anatomical structure and trackinga motion of the at least one anatomical structure using imaging beforeand during delivery of a therapy to a patient, includes: an imagingmodule configured to identify a location and a feature of a region ofthe anatomical structure in an image, wherein the imaging modulecomprises a tracker, a detector, and an integrator; and a therapy modulecomprising an ultrasound treatment transducer configured to deliver thetherapy to a target tissue in the patient.

Optionally, the imaging module is configured to, in real-time, track theanatomical structure using a feature identification technique.

Optionally, the imaging module is configured to use a histogram of theanatomical structure in the image, or a feature matching technique.

Optionally, the imaging module is configured to identify a location ofthe target tissue to be treated by the therapy module.

Optionally, the tracker is configured to identify a new location or anew feature of the region of the anatomical structure in response to achange in the location and the feature of the region of the anatomicalstructure.

Optionally, the detector is configured to identify a shape, a location,and a feature of the region of the anatomical structure.

Optionally, the tracker, detector, and integrator are implemented ingraphics processor unit (GPU), field-programmable gate array (FPGA) ordigital signal processor (DSP) or any other units containing computationcapabilities.

Optionally, the therapy module is configured to function concurrentlywith the imaging module.

Optionally, the therapy module is configured to deliver therapy to thetarget tissue despite a change in the location or the feature of theregion of the anatomical structure.

Optionally, the anatomical structure comprises the target tissue.

Optionally, at least one of breathing, blood flow, conscious movement,or unconscious movement of the patient changes the location and/or thefeature of the region of the anatomical structure.

Optionally, the imaging module is configured to identify the locationand the feature of the region of the anatomical structure in less than 1second.

Optionally, the imaging module is configured to identify the locationand the feature of the region of the anatomical structure in less than 5milliseconds.

Optionally, the target tissue comprises a renal artery.

Optionally, the ultrasound treatment transducer is configured to providerenal denervation.

Optionally, the imaging module is configured to track the region of theanatomical structure is using a B-mode image, Harmonic Imaging, or 3Dultrasound imaging.

Optionally, the imaging module is configured to track the region of theanatomical structure using a color Doppler image, a color power Dopplerimage, or a directional color power Doppler mode image.

Optionally, the system further includes a filter, wherein the filter isconfigured to reduce noise in the image, such that the imaging modulecan determine the location and the feature of the region of theanatomical structure in the image.

Optionally, the filter is configured to provide a filtered image that isvisible to the tracker, the detector, or both the tracker and detector.

Optionally, the system further includes a user interface for allowing auser to choose between viewing the filtered image or an unfilteredimage.

Optionally, the location is an x and y coordinate.

Optionally, the location is an x, y, and z coordinate.

Optionally, the image is an ultrasound image.

Optionally, the integrator is configured to integrate results from thetracker and detector and direct the therapy module to deliver thetherapy to the target tissue.

Optionally, the location is in a plane.

Optionally, the location is in a three-dimensional space.

Optionally, a plane of movement of the anatomical structure issubstantially parallel to an imaging plane of the imaging module.

Optionally, the feature includes one or more of a characteristic,intensity, density, contrast, and shape of the region of the anatomicalstructure.

Optionally, the imaging module and the therapy module are configured tofunction consecutively using an interleaving mechanism.

Optionally, the imaging module and the therapy module are configured tofunction concurrently using a continuous mechanism.

Optionally, the therapy module is configured to predict a futurelocation or a future feature of the target tissue and to deliver thetherapy to the target tissue when the target tissue reaches the futurelocation or the future feature.

Optionally, the therapy module is configured to provide lithotripsy.

Optionally, the lithotripsy comprises treatment of a kidney stone,gallstone, bile duct stone, or ureter stone.

Optionally, the tracker comprises a short-term detector.

Optionally, the detector comprises a long-term detector.

A system for tracking a renal artery during delivery of an ultrasoundtherapy to a patient, includes: an imaging module configured to identifya location and a feature of a region of an anatomical structure in anultrasound image, wherein the imaging module comprises a tracker, adetector, and an integrator; and a therapy module comprising anultrasound treatment transducer configured to deliver the ultrasoundtherapy to the renal artery, wherein the ultrasound treatment transduceris configured to be mechanically moved and/or electronically controlled.

Optionally, the ultrasound treatment transducer is configured to bemoved by a motion control mechanism to move the ultrasound treatmenttransducer.

Optionally, the ultrasound treatment transducer comprises a fullcircular annular phased array.

Optionally, the ultrasound treatment transducer comprises a partialcircular annular phased array.

Optionally, the ultrasound treatment transducer is configured to bedirected and moved to guide therapeutic energy to the renal artery.

Optionally, the ultrasound treatment transducer comprises atwo-dimensional array and is configured to move therapy focus by athree-dimensional electronic control mechanism to guide therapeuticenergy to the renal artery.

Optionally, the ultrasound treatment transducer is configured to bemoved by a mechanical control mechanism to guide therapeutic energy tothe renal artery.

A method for imaging during delivery of a therapy, includes: acquiringan image of a body portion of a patient; identifying a region of ananatomical structure that has a relationship to a target tissue in theimage; tracking a location and/or a feature of the region of theanatomical structure in the image; integrating results from the act oftracking; generating a template library to cover possible changes of thelocation and/or changes of the feature of the region of the anatomicalstructure; and delivering the therapy to the target tissue whiletracking the region of the anatomical structure in the image.

Optionally, the method further includes continuously delivering therapyto the target tissue despite a change in one or more locations andfeatures of the region of the anatomical structure.

Optionally, the act of tracking occurs in response to a change in thelocation or the feature of the region of the anatomical structure.

Optionally, the region of the anatomical structure comprises the targettissue.

Optionally, at least one of breathing, blood flow, conscious movement,or unconscious movement of the patient changes the location and/or thefeature of the region of the anatomical structure.

Optionally, the region of the anatomical structure is undetectable bythe imaging module as a result of at least one of breathing, blood flow,conscious movement, and unconscious movement.

Optionally, the method further includes stopping imaging of the bodyportion of the patient when the region of the anatomical structure isundetectable.

Optionally, the method further includes automatically re-detecting theregion of the anatomical structure location or feature.

Optionally, the automatically recovering step further comprisesautomatically recovering the region of the anatomical structure locationor feature by first determining a last known location or feature of theregion of the anatomical structure in the image.

Optionally, the act of tracking occurs in less than 5 milliseconds.

Optionally, the act of delivering the therapy comprises denervatingrenal nerves surrounding the renal artery.

Optionally, the act of delivering comprises delivering ultrasound to thetarget tissue.

Optionally, the act of tracking comprises using a B-mode image, HarmonicImaging, or 3D ultrasound imaging.

Optionally, the act of tracking comprises using a color Doppler image, acolor power Doppler image, or a directional color power Doppler modeimage.

Optionally, the act of tracking comprises using an image in B-mode,Harmonic mode, color Doppler mode, color power Doppler mode, acombination of the B-mode, the Harmonic mode and the color Doppler mode.

Optionally, the method further includes filtering the image to obtain afiltered image, such that the anatomical structure can be tracked in thefiltered image.

Optionally, the method further includes determining if a pre-existingtemplate matches a result from the act of tracking.

Optionally, the method further includes determining if a result from theact of tracking should be updated as a new template.

Optionally, a position of the target tissue is based on the pre-existingtemplate and a new template. For example, averaging (e.g., weightedaveraging, non-weighted averaging) may be performed using information inthe pre-existing template and the new template to determine the positionof the target tissue.

Optionally, the method further includes generating a new template when apre-existing template does not match a result from the act of tracking,wherein the new template defines or indicates a location and a shape ofthe target tissue.

A method for treatment includes: acquiring with an imaging module animage of a body portion of a patient; identifying a region of ananatomical structure that has a relationship to a target tissue in theimage; tracking a location and/or a feature of the region of theanatomical structure in the image; transforming a target position of thetarget tissue from an imaging space associated with the imaging moduleto a treatment space associated with a therapy module through one ormore position sensors and a transmitter; and delivering a therapy withthe therapy module to the target tissue while tracking the region of theanatomical structure.

Optionally, the one or more position sensors and the transmitter areconfigured to link a position of an imaging transducer of the imagingmodule to a position of an ultrasound treatment transducer of thetherapy module.

Optionally, the one or more position sensors comprises a magneticsensor, an optical sensor, an ultrasound sensor, or a mechanicalposition sensor.

Optionally, the one or more position sensors are mounted on an imagingtransducer of the imaging module.

Optionally, the transmitter is mounted on an imaging transducer of theimaging module.

Optionally, the one or more position sensors are mounted on anultrasound treatment transducer of the therapy module.

Optionally, the transmitter is mounted on an ultrasound treatmenttransducer of the therapy module.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a system for tracking a target tissue and deliveringtherapy to a target tissue, in accordance with a preferred embodiment;

FIG. 2 illustrates a tracking algorithm, in accordance with a preferredembodiment;

FIGS. 3A and 3B illustrate images used for tracking and delivery oftherapy to a target tissue, in accordance with a preferred embodiment;

FIG. 4 illustrates a flow chart for the functioning of a tracker, inaccordance with a preferred embodiment;

FIG. 5 illustrates a tracker algorithm, in accordance with a preferredembodiment;

FIG. 6 illustrates a flow chart for the functioning of a detector, inaccordance with a preferred embodiment;

FIG. 7 illustrates a detector algorithm, in accordance with a preferredembodiment;

FIG. 8 illustrates a flow chart for the functioning of an integrator, inaccordance with a preferred embodiment;

FIGS. 9A and 9B illustrate a system including a filter for tracking atarget tissue and delivering therapy to a target tissue, in accordancewith a preferred embodiment;

FIG. 10 illustrates a therapy module, in accordance with a preferredembodiment;

FIG. 11 illustrates a system including an imaging and therapy module, inaccordance with a preferred embodiment;

FIGS. 12A and 12B illustrate an interleaving and a continuous mechanismfor imaging and therapy delivery, respectively, in accordance with firstand second preferred embodiments; and

FIG. 13 illustrates a method of tracking a target tissue and deliveringtherapy to a target tissue, in accordance with a preferred embodiment.

DETAILED DESCRIPTION

The following description of the preferred embodiments of the inventionis not intended to limit the invention to these preferred embodiments,but rather to enable any person skilled in the art to make and use thisinvention. Disclosed herein are systems and methods for identifying atleast one anatomical structure and tracking the motion of the at leastone anatomical structure using imaging before and during delivery of atherapy to a patient.

Described herein are systems and methods for tracking an anatomicalstructure in a patient and delivering therapy to an anatomicalstructure. The structure receiving the delivered therapy from the systemis the target tissue. In some embodiments, the system may functioncompletely non-invasively. Alternatively, the system may additionallyinclude catheterization or otherwise surgically manipulating thepatient. The system may be used to track an anatomical structure, suchas an organ, blood vessel, artery, bone, blood, or any other type ofanatomical structure. For example, in some embodiments, the system mayfunction to track a kidney or renal artery of a patient. Alternatively,the system may be used to track a region of an anatomical structure,such as a curved edge or surface, a more distal or proximal portion ofan organ, blood flow through a vessel, a distinguishing feature of anorgan, for example glomeruli of the kidney, or any other region ofinterest of an anatomical structure. In some embodiments, a feature ofan anatomical structure may be tracked, such as a location, shape,intensity, contrast, density, or otherwise characteristic of theanatomical structure. The location of an anatomical structure mayinclude an x, y coordinate or an x, y, z coordinate. Alternatively, thelocation of the anatomical structure may be tracked in a two-dimensionalplane or in three-dimensional space. The tracked anatomical structuremay be a different structure than the anatomical structure receivingtherapy from the system, such that a change in location or feature ofthe anatomical structure indicates a change in position of the targettissue. Alternatively, the anatomical structure may be the same as thetarget tissue, such that the target tissue is the anatomical structurethat is being tracked. In some embodiments, the tracked anatomicalstructure may be a kidney and the target tissue receiving therapy may bea renal artery.

In some embodiments, the system may deliver therapy via ultrasound,mechanical vibrations, electromagnetic waves, lasers, X-ray or any othertype of non-invasive radiation therapy. The therapy may include renaldenervation, kidney stone disruption, gallstone disruption, bile ductstone disruption, ureter stone disruption, or any other type ofnon-invasive therapy.

In general, an anatomical structure may be lost and/or move duringtracking and/or while receiving therapy. For example, an anatomicalstructure may be lost due to a shadow from another organ or bonestructure, for example the rib cage. Alternatively or additionally, ananatomical structure may move due to breathing, blood flow, consciousmovement, or unconscious movement of the patient during the procedure.In some instances, the region of the anatomical structure may becomeundetectable by the system as a result of breathing, blood flow,conscious movement, or unconscious movement of the patient. For example,an anatomical structure may move approximately 2 cm/second. In someinstances, the anatomical structure may move substantially in a planeparallel to the plane of the system, or principal plane. Alternatively,the anatomical structure may move perpendicularly or variably relativeto the system. As described herein, the system is configured to track aregion of an anatomical structure despite shadows or deep breathing by apatient that moves an anatomical structure out of sight.

In some embodiments, the system may utilize an imaging module to locatethe target tissue and track the position and/or movements of the targettissue, such that the therapy module can maintain its focus on thetarget tissue during the treatment process. In some embodiments, theimaging information may be used to confirm that the focus of the therapymodule is properly positioned over the treatment region. The system thencalculates the treatment parameter, such as dosing of ultrasound energyto be applied to the treatment region. For example the physician mayenter the desired dosing level for a particular treatment. The systemmay also take into account other parameters, such as the distance of thetarget region from the therapy module, and calculate the appropriateultrasound energy to apply to achieve the desired dosing at the targetregion. A particular treatment plan, such as a specific treatmentpattern (e.g., energizing multiple spots within a treatment area), and aspecific dosing routine (e.g., spreading a dose into multiple quantizeddelivery over a finite period of time to achieve the desired dose) maybe selected. The system may then implement the treatment plan, andultrasound energy may be delivered to the treatment region based on thetreatment plan. In some embodiments, the treatment plan includessequential lesions offset from the blood flow of a vessel and within 5mm of one another. In another embodiment, the treatment plan includessequential lesions offset from the blood flow and within 1 mm of eachother. In another embodiment, the sequential lesions do not have anoffset from one another and sequential lesions are applied atop oneanother in substantially the same position.

FIG. 1 illustrates a system 100 for tracking a region of an anatomicalstructure and delivering therapy to a target tissue, in accordance witha preferred embodiment. The system according to FIG. 1 preferablyfunctions to image one or more anatomical structures, track a locationor a feature of the anatomical structure, and delivery therapy to atarget tissue. As shown in FIG. 1, a system 100 for identifying at leastone anatomical structure and tracking the motion of the at least oneanatomical structure using imaging before, during, or after delivery ofa therapy to a patient includes an imaging module 101 and a therapymodule 102. The imaging module 101 may be configured to acquire animage, identify one or more locations and/or features of an anatomicalstructure in the image, and/or track a location and/or feature of theanatomical structure within the image. The therapy module 102 of thesystem 100 may be configured to deliver therapy to a target tissue

In some embodiments, the therapy module 102 may include a therapy energydelivering subsystem 107, which functions to generate controlledelectrical energy to the ultrasound treatment transducer 108. In someembodiments, the ultrasound treatment transducer 108 transmits theultrasound energy into the targeted tissue structure in a human body. Insome embodiments, the ultrasound treatment transducer 108 may be a fullcircular annular phased array transmitting the focused ultrasound energyalong the acoustic axis in depth direction into the targeted tissuestructure in a human body. In other embodiments, the ultrasoundtreatment transducer 108 may be a section of full (e.g., partial)circular annular phased array transmitting the focused ultrasound energyalong the acoustic axis in depth direction into the targeted tissuestructure in a human body. For example, the transducer may have a pieshape so that the shape is less than a full circular shape. In someembodiments, the therapy module 102 may include a tip/tilt motioncontrol unit 109 that adjusts the ultrasound treatment transducerrotation in tip and tilt directions to follow the targeted tissuemotion. In other embodiments, the following of the targeted tissuemotion may be accomplished by electronic control of the phasing of theultrasound elements in the ultrasound treatment transducer, therebyobviating the need to mechanically move the ultrasound treatmenttransducer. In further embodiments, the control of the ultrasound energyfocus may be accomplished using both electronic phasing control ofultrasound elements in the ultrasound transducer 108 and mechanicalcontrol of the movement of the ultrasound transducer 108 by the therapymodule 102. In some cases, such technique may allow control ofultrasound energy focus at any position within a huge treatment volumein 3D space. In some embodiments, the therapy module 102 may furtherinclude a transmitter and/or one or more position sensors of a 3Dposition system 110.

In some embodiments, the imaging module 101 may include an imageacquisition subsystem 103 that functions to acquire an image. In someembodiments, the image acquisition subsystem 103 may use ultrasound toacquire images of a region of an anatomical structure. In someembodiments, the imaging module 101 may further include an imagetracking system 104 that functions to track a location and/or feature ofan anatomical structure within the image acquired by the imageacquisition subsystem 103. In some embodiments, the imaging module 101may include an ultrasound imaging transducer 105 that transmits theultrasound signals into the human body and receives the reflected signalfrom the tissue structures. In some embodiments, the imaging module 101may further include position sensors 106 that are attached to theimaging transducer 105 to acquire the position of the imaging transducer105 in 3D space and feed the position information to the imagingtracking subsystem 104. In some embodiments, the imaging transducer 105may be linear, curved linear, phased, annular, or other types of imagingarrays that acquire an imaging plane inside a human body. In someembodiments, the imaging transducer 105 may be a two-dimensional arraythat acquires 3D ultrasound images inside a human body.

In some embodiments, the 3D position system determines the position ofthe ultrasound treatment transducer 108 and the relationship of thepositions between the imaging transducer 105 and ultrasound treatmenttransducer 108. In some embodiments, an imaging ultrasound transducer105 may be included near the therapy module 102, such that images may beacquired of the region of the anatomical structure being targeted,tracked, and treated as will be described below.

In some embodiments, the imaging module may acquire an ultrasound image.For example the imaging module may use echoes of ultrasound pulses todelineate objects or areas of different density in the body. A frequencyrange used may be between 0.5 to 18 megahertz or up to 50 or 100megahertz. Alternatively, x-ray, computed tomography, magneticresonance, or any other type of imaging modality, optical or otherwise,may be used. In some embodiments, the imaging of an anatomical structuremay be acquired in a B-mode image, Harmonic image, a color Dopplerimage, a color power Doppler image, a directional color power Dopplermode image, any other type of image, or any combination of two or moreof the foregoing. For example, in a B-mode image and/or Harmonic image,the system may image a two-dimensional cross-section of the tissue.Alternatively or additionally, the system may utilize color Dopplerimaging, an imaging technique that combines anatomical informationderived using ultrasonic pulse-echo techniques with velocity informationderived using ultrasonic Doppler techniques to generate color-coded mapsof tissue velocity superimposed on grey-scale images of tissue anatomy.Further, color power Doppler imaging has increased intensity and theadded benefit of depicting flow in small vessels.

In some embodiments, the imaging module 101 may function to identify aposition of a region of an anatomical structure, such that the therapymodule 102 may deliver therapy in a substantially continuous manner tothe target tissue. The imaging module 101 may rapidly identify theposition of the target tissue such that the therapy module 102 may thenrapidly deliver therapy to the target tissue. In an interleavingpattern, the position may be identified, followed by therapy delivery,followed by position identification, and so on. This interleavingpattern of the imaging module and therapy module may occur in rapid,repetitive succession such that therapy is delivered substantiallycontinuously. The rapid, repetitive succession is required, such thatthe target tissue may be tracked substantially continuously and thetherapy may be delivered substantially continuously.

In some embodiments, the imaging module 101 may function rapidly, suchthat a dose of therapy may be delivered substantially continuously tothe target tissue without significant delay between identifying aposition of the target tissue and delivering therapy to the targettissue or between subsequent doses of therapy to the target tissue. Forexample, the imaging module 101 may identify one or more locationsand/or features of the region of the anatomical structure in less than10 seconds, 5 seconds, 3 seconds, 2 seconds, or 1 second. Alternatively,the imaging module may identify one or more locations and/or features ofthe region of the anatomical structure in less than 1000 milliseconds,750 milliseconds, 500 milliseconds, 250 milliseconds, 100 milliseconds,75 milliseconds, 50 milliseconds, 25 milliseconds, 10 milliseconds, 5milliseconds, or 1 millisecond. In some embodiments, the imaging modulemay use a frame rate of greater than or equal to 20 Hz. Alternatively,the imaging module may use a frame rate of less than 20 Hz.

Returning to FIG. 1, in some embodiments, the image tracking subsystem104 of imaging module 101 includes a tracker and a detector. Both thetracker and detector are computer algorithms configured to identify andtrack a shape, location, and/or feature of a region of an anatomicalstructure in an image by searching within a region of interest in theimage for a shape, location, and/or feature of the region of theanatomical structure. As described below in further detail, the imagingmodule 101 may weigh results from the tracker and detectordifferentially, such that in some instances only the tracker results maybe used or, alternatively, only the detector results or both. In someembodiments, the tracker and detector may each independently identifyand track a shape, location, and/or feature of a region of an anatomicalstructure in an image. The tracker and detector may identify motion of aregion of an anatomical structure and compensate for the motion byadjusting the focal point, such that therapy may be deliveredsubstantially continuously to a target tissue. In some embodiments, asystem may use both a tracker and detector to identify and track aregion of an anatomical structure in an ultrasound image. The trackerand the detector complement each other, increase robustness of thesystem, and compensate for non-uniformity of ultrasound waves (ascompared to imaging with light) in their interactions with an object ortissue being imaged.

In some embodiments, the tracking capabilities of the tracker anddetector may be combined into one algorithm, negating the need for aseparate tracker and detector. In some embodiments, results from thetracker and detector may be compared to templates, which identify aprevious shape, location, and/or feature of the region of the anatomicalstructure. For example, the tracker may be a short-term detector in thatthe results are compared to several previous image (I_(n-p), I_(n-p-1),. . . I_(n-3), I_(n-2), I_(n-1)) and use weighted function to obtain thefinal position. In some embodiments, the tracker will first look forchange near the previous location (i.e. previous image (I_(n-1)) ratherthan looking throughout the entire image. Further for example, thedetector may be a long-term detector in that the results are compared tomore than one template (i.e. a template pool) from any number ofprevious images. In some embodiments, the long-term template managementsamples breathing cycles. In general, the combination of thecomplimentary tracker and detector will enable the system to compensateautomatically, without user intervention, if the target becomes lost orunfocused. Alternatively, any quantity and/or type of trackers and/ordetectors may be used. In some embodiments, the system may includeadditional trackers and/or detectors such that the additional trackersand/or detectors complement the existing trackers and detectors fortracking a region of an anatomical structure. In some embodiments, themultiple complementary trackers and/or detectors may lead to anincreased computation time and/or memory requirements, however therobustness of the system will also improve. In some embodiments, thesystem 100 further includes an integrator. The integrator is analgorithm configured to compare and/or integrate the results fromtracker and detector of the image tracking subsystem of the imagingmodule 101 and direct the therapy module 102 to deliver the therapy tothe target tissue.

The tracker and detector are algorithms for determining a locationand/or feature of a region of an anatomical structure. In someembodiments, as shown in FIG. 2, a feature histogram algorithm may beused. Feature histogram describes the two-dimensional spatialdistribution of the featured pixels in a defined area or analysis region201. As shown in FIG. 2, the analysis region 201 may be equally dividedinto several smaller regions. The analysis region 201 containing 6 by 6pixels, as shown in FIG. 2, is subdivided into 4 sub-regions 202, whichcontains 3 by 3 pixels 203. However, it should be understood that anynumber of pixels in analysis region 201 may be used, for example lessthan 36 pixels or more than 36 pixels. For example, a 5×5, 75×75,100×100, 500×500, or 1000×1000 pixels, or anything above, below orin-between may be utilized.

In some embodiments, as shown in FIG. 2, a pixel 203 of an anatomicalstructure may be identified, for example by contrast, pixel density, orintensity, in the analysis region 201, denoted by an “x” in the pixel203. Each “x” or pixel feature may be totaled for each sub-region,resulting in a 2 by 2 feature histogram 204 of region 201. The 2 by 2feature histogram 204 is further normalized into a 2 by 2-normalizedfeature histogram 205. The distribution of the feature histogramsindicates a location or feature of the region of the anatomicalstructure. However, it should be understood that any number of histogramdimension can be used, for example 4 by 4, 8 by 8, 8 by 4, 4 by 8, 16 by16, 16 by 8, 8 by 16, 32 by 32 or any other number.

In some embodiments, a first feature histogram indicating a firstlocation or feature of a region of an anatomical structure may becompared to second feature histogram indicating a second location orfeature of the region of the anatomical structure. In some embodiments,the first or second feature histogram may include a template from aprevious image. The two histograms may be compared using equation (1)below, where H₁ ^(ij) is the first feature histogram, H₂ ^(ij) is thesecond feature histogram, N is the total number of bins in thex-direction of the 2D feature histogram, M is the total number of binsin the y-direction of the 2D feature histogram, and D is the distancebetween the two histograms between 0 and 1. When D=0, the two histogramsare identical. Conversely, when D=1, the two histograms are the mostdifferent.

$\begin{matrix}{D = \sqrt{1 - {\sum\limits_{i = 1}^{N}{\sum\limits_{j = 1}^{M}\sqrt{H_{1}^{ij}H_{2}^{ij}}}}}} & (1)\end{matrix}$

In some embodiments, alternative algorithms may be employed, such as sumsquared difference, sum absolute difference, or normalized crosscorrelation (NCC). For example, in NCC, a position of the region of theanatomical structure is determined by a pixel-wise comparison of thecurrent image with the template containing a previous position of theregion of the anatomical structure. The search region in the template isshifted in discrete steps in the N and M directions, and then thecomparison is calculated (i.e. subtracting the mean and dividing by thestandard deviation at every step) over the template search area for eachposition. The position of the maximum NCC values indicates the positionof the region of the anatomical structure in the current image.Alternatively, any other threshold NCC value (i.e. minimum) may be used.

FIGS. 3A and 3B illustrate a region of an anatomical structure that isbeing tracked by two tracking boxes 302, 303 working on different tissueareas, in and around a region 301 that is viewable by a user. Eachtracking box is associated with its own tracker, detector, andintegrator. As shown in FIG. 3, two tracking boxes 302, 303 are used toincrease the robustness and fidelity of the system, such that both thefirst and second tracking boxes are tracking a similar region of theanatomical structure in each of the tracking boxes 302, 303. Tracking isnot completely lost and therapy is not stopped unless both boxes losetracking. For example, if the first tracking box (associated withtracker, detector, and integrator) becomes lost and/or is unable to findthe region of the anatomical structure, the second tracking box(associated with tracker, detector, and integrator) will continuetracking the region of the anatomical structure and therapy deliverywill continue and vice versa.

In this example, the tracking boxes are tracking a location or featureof a region of an anatomical structure in two images, at opposite endsof a breathing cycle, using a feature histogram algorithm, as describedabove. For example, a beginning of a breathing cycle is shown in FIG. 3Aand an end of a breathing cycle is shown in FIG. 3B. The crosshairs 304indicate a target region or tissue for receiving therapy. As shown inFIG. 3, the target tissue (e.g. renal artery) receiving therapy isdistinct from the regions of the anatomical structure (e.g. tissue) thatis being tracked by the tracking boxes. In some embodiments, the searchregion may be any size, for example 361 pixels by 420 pixels.Alternatively, the search region may be larger than 361 pixels by 420pixels or less than 361 pixels by 420 pixels. The tracking boxes 302,303 may be any size, for example 64×64 pixels. Alternatively, thetracking boxes may be less than 64×64 pixels or greater than 64×64pixels. In some embodiments, a user may select the tracking box size.Alternatively, the tracking box size may be selected automatically bythe system. Alternatively, only one tracking box or more than twotracking boxes may be used. In some embodiments, the system may includeadditional tracking boxes to add redundancy to the system. In someembodiments, the multiple complementary trackers and/or detectors maylead to an increased computation time and/or memory requirements,however the robustness of the system will also improve.

In some embodiments, the tracking performed by the first and secondtracking boxes may occur with an accuracy of root-mean-square (RMS)error of less than or equal to 2 mm. Alternatively, the RMS error may bemore than 2 mm, but still within a suitable accuracy. In someembodiments where two tracking boxes are used, if both the trackingboxes 302, 303 are lost, the tracking boxes 302, 303 may recover at thesame time and maintain the same relative position with error within lessthan or equal to 40 pixels. Alternatively, the error may be within morethan 40 pixels. Further, in some embodiments, if the region of theanatomical structure moves outside of the image, the tracker anddetector will cease to track the region of the anatomical structure.

In some embodiments, as shown in FIG. 4, a tracker may function as ashort-term detector, as described above. The tracker may compare afeature histogram of a current location or feature of a region of ananatomical structure in a current image (I_(n)) to a template. In someembodiments, the template may be a feature histogram of a previouslocation or feature of the region of the anatomical structure in aprevious image (I_(n-1)). In some embodiments, the tracker may searchfor a change in a region of the anatomical structure near a previouslocation of the region of the anatomical structure in the templateinstead of searching an entire template. The two feature histograms arecompared, for example using equation (1), and the minimum distance Dbetween the two feature histograms may be determined and the x, ycoordinates of the point of the minimum distance D may be identified, asshown in FIG. 4. Alternatively, a maximum distance D or any otherthreshold may be used when comparing two or more feature histograms.

As shown in FIG. 5, within the search region 501, the tracker tracks apossible current location or feature 502 of a region of the anatomicalstructure in the current image (I_(n)). The previous location or feature(with M, N coordinates) of the region of the anatomical structure fromimage (I_(n-1)) is a template 503, as described above. In someembodiments, the tracker may search for a change in a region of theanatomical structure near a previous location of the region of theanatomical structure instead of searching the entire image. The distancebetween the feature histograms of the possible current location orfeature 502 and the previous location or feature 503 of the region ofthe anatomical structure is calculated. Each of the distances may berepresented by value D, such that the minimum D value and the positionof the minimum D value indicate a best match between a current locationor feature and a previous location or feature of the region of theanatomical structure in the template.

As shown in FIGS. 6 and 7, within the search region 701, the detectormay function as a long-term detector, as described above. The detectormay detect a possible current location or feature of a region of theanatomical structure in a current image (I_(n)). The feature histogramof the possible current location or feature 702 in a current image I_(n)is compared to a template pool 704 comprising feature histograms for oneor more templates of previous locations and/or features, for example703, of the region of the anatomical structure in previous images(I_(n-1)). For example, a template pool 704 may include a plurality oftemplates. As one example, the template pool 704 may include 64templates. The feature histograms of the possible current location orfeature 702 of a region of the anatomical structure are compared to thefeature histograms of the one or more templates, for example 703,through calculating the D value. The template corresponding to theminimum D value and the position of the minimum D value indicates a bestmatch between a current location or feature 702 and the template fromthe template pool 704, identifying the location or feature as the regionof the anatomical structure 701, as shown in FIG. 7. In someembodiments, a maximum Normalized Cross Correlation (NCC) value maycorrespond to a best match between a current location or feature and thetemplate from the template pool, which could replace the D value asdescribed above.

In some embodiments, the feature histogram of the current image iscompared to all templates in the template pool. Alternatively, thefeature histogram of the current image may be compared to a subset ofthe template pool. In some embodiments, all templates search in theirown search regions and the region of the anatomical structure is at theposition, which gives the maximum (i.e. NCC value) or minimum value(i.e. sum squared difference value) in all search regions of thetemplates.

FIG. 8 illustrates an integrator flow chart. In some embodiments, asshown in FIG. 8, an integrator is an algorithm that compares thetracking results from the tracker and detector and determines (1) if theresults from the tracker or detector should be used in determining acurrent location or feature of the region of the anatomical structureand (2) if the results from the tracker and detector should be added asa template to the template pool. In some embodiments, the integratorweighs the results of the detector more heavily. As shown in FIG. 8, ifthe results from the detector match with a key template, which is atemplate sampled throughout the motion cycles, then the integrator willuse the detector results 802. Otherwise, if the distance value Ddetermined by the detector is less than the distance value D determinedby the tracker 803, the integrator will use the results from thedetector 804, such that the smaller distance value D from the detectormore accurately defines the feature histogram of the location orfeature. Alternatively, if the distance value D determined by thedetector is more than the distance value D determine by the tracker,then the integrator further evaluates the results from the tracker 805.If the distance value D is greater than a predetermined threshold or ifthe distance of the current location to the closest template location isgreater than a predefined pixel distance (L), for example 3√{square rootover (2)} or any other distance, the feature histogram denoted bydistance value D will be updated as a template and maintained as part ofthe template pool 807. In some embodiments, if the location of a currentfeature is a predefined distance (L) from all other templates in thepool, then the current feature will be saved as a “key” template. Any ofthe above integrations performed by the integrator may be sent to thetherapy module, such that an x, y, z coordinate of the current locationmay be sent to the therapy module and the therapy module may delivertherapy to the target tissue, as shown in FIG. 8. In some embodiments,the time between the therapy module receiving instructions anddelivering therapy is less than or equal to 50, 40, 30, 20, 10, 5, or 1milliseconds. Alternatively, the time between receiving instructions anddelivering therapy may be more than 50 milliseconds.

In some embodiments, as shown in FIG. 9A, a system 900 for tracking aregion of an anatomical structure and delivering therapy to a targettissue may further include a filter 901. The filter may use an algorithmto reduce noise in the image (I_(n)), such that the imaging module 902may determine one or more locations and/or features of the region of theanatomical structure in the image (I_(n)). In some embodiments, thenoise may include speckle, multiple coherent reflections from theenvironment surrounding the region of the anatomical structure or targettissue, or any other type of noise. In some embodiments, the filteredimage may be visible only to one of the tracker or detector.Alternatively, both the tracker and detector may use the filtered image.In some embodiments, a user of the system 900 may select between viewingthe filtered image or an unfiltered image.

In some embodiments, as shown in FIG. 9B, a filter may use a simplemoving average filter to remove noise in an image (I_(n)). As shown inFIG. 9B, each region 903 of the image may be identified (i_(n)) and theaverage intensity of the pixels in each region may be determined.Equation (2) may be used to smooth the image, such that y[i] equals thesmoothed pixel intensity, M equals the number of regions 903 in theaverage, i equals the location of smoothed pixel, and j equals the indexwithin the region. Alternatively, any other type of filtering equationmay be used.

$\begin{matrix}{{y\lbrack i\rbrack} = {\frac{1}{M}{\sum\limits_{j = 0}^{M - 1}{x\lbrack {i*j} \rbrack}}}} & (2)\end{matrix}$

In some embodiments, where the integrator integrated the results fromthe tracker and detector, as described above with respect to FIG. 8, thetherapy module may receive a current target tissue location and adistance to the current target tissue location from the integrator. Insome embodiments, the therapy module 1000 may include one or moreultrasound transducers 1001, 1002, as shown in FIG. 10. The therapymodule 1000 may include a phased or fixed array of ultrasoundtransducers 1002 for delivering therapy to the target tissue. Further,in some embodiments, as shown in FIG. 10, the therapy module may includea second phased or fixed array of ultrasound transducers 1001 foracquiring images of the region of the anatomical structure. The regionof the anatomical structure may then be tracked in the image by thetracker and detector, as described above. As shown in FIG. 11, thetherapy module 1000 may be integrated into a patient platform 1030, suchthat the therapy module 1000 is positioned in a cavity 1010 of thepatient platform 1030 while maintaining access to a patient lying on thepatient platform 1030. In some embodiments, the imaging module 1020 maybe in the same room and/or electrically connected to the patientplatform 1030 and/or the therapy module 1000. Alternatively, the imagingmodule 1020 may be in communication with the therapy module 1000 throughBluetooth, Wi-Fi, or any other type of connection. Other features andaspects of the system 1050 of FIG. 11 are disclosed in PCT ApplicationSerial Number 2014/022141, which is herein incorporated by reference.

In some embodiments, the ultrasound transducer of the therapy module maybe moved, repositioned, or otherwise relocated by a motion controlmechanism. Alternatively, the ultrasound transducer of the therapymodule may be directed and moved to guide therapeutic energy to thetarget tissue, for example by an applicator 1060. In some embodiments,the ultrasound transducer of the therapy module may be moved by athree-dimensional electronic beam steering control mechanism to guidetherapeutic energy to the target tissue. Alternatively, the ultrasoundtransducer of the therapy module may be moved by a mechanical controlmechanism to guide therapeutic energy to the target tissue.

In some embodiments, as shown in FIG. 12A, the imaging module andtherapy module may function in rapid succession in an interleavingmechanism. FIG. 12A illustrates the interleaving pattern with solidarrows representing hard sync triggers and dashed arrows representingsoft sync triggers. The interleaving pattern, as shown in FIG. 12A, maycontinue until the prescribed dose of therapy has been delivered. Insome embodiments, the therapy module will be re-targeted to a new lesionor position and the interleaving mechanism will resume. Alternatively,in some embodiments, the imaging module and therapy module may functionsimultaneously, such that therapy is continuously being delivered whilethe imaging module is transmitting tracker and detector results to thetherapy module, as shown in FIG. 12B. Alternatively or additionally, thetherapy module may function using a predictive mechanism, such that thetherapy module may predict a future position of the region of theanatomical structure that is being tracked by the imaging module fromseveral previous target positions and move to that predicated positionto deliver therapy.

FIG. 13 illustrates a method of tracking a target tissue and deliveringtherapy to a target tissue, in accordance with a preferred embodiment.As shown in FIG. 13, a method for imaging during delivery of a therapyof a preferred embodiment includes the steps of acquiring an image of abody portion of a patient S100; identifying a region of an anatomicalstructure that has a relationship to a target tissue in the image S110;tracking a location or feature of the region of the anatomical structurein the image S120; integrating the results from the tracking S130;generating a unique template library to cover possible changes of theone or more locations and features of the region of the anatomicalstructure S140; determining if a pre-existing template matches a resultfrom the tracking or if the result should be updated as a new template,wherein the pre-existing template and the new template define a positionof the target tissue in the image S150; and delivering the therapy tothe target tissue while tracking the region of the anatomical structurein the image S160. In some embodiments, the method preferably functionsto track a region of an anatomical structure, such that the position ofthe anatomical structure correlates with a position of a target tissue.The method may be used for delivering ultrasound to denervate a renalartery but, additionally or alternatively, can be used for any suitableapplications, clinical or otherwise. For example, the method may be usedto deliver ultrasound to a kidney, gallbladder, bile duct, or ureter todisrupt kidney, gallstones, bile duct stones, or ureter stones,respectively.

As shown in FIG. 13, step S100 includes acquiring an image of a bodyportion of a patient. Step S100 preferably functions to image a regionof an anatomical structure of a patient, such that a location and/orfeature of a region of the anatomical structure may correspond to aposition of the target tissue for receiving therapy. As described above,the image may be acquired in B-mode, Harmonic image, color Doppler,color power Doppler, or directional color power Doppler mode image. Insome embodiments, the imaging may be performed using ultrasound or anyother type of imaging modality, optical or otherwise.

As shown in FIG. 13, step S110 includes identifying a region of ananatomical structure that has a relationship to a target tissue in theimage. Step S110 preferably functions to identify a region of ananatomical structure that moves, deforms, or otherwise tracks in asimilar manner as the target tissue, such that the anatomical structuremay be tracked while the target tissue is receiving therapy. Forexample, if the target tissue moves 2 cm to the right in the image, theregion of the anatomical structure being tracked should also move 2 cmto the right. In some embodiments, the target tissue is the anatomicalstructure being tracked.

As shown in FIG. 13, step S120 includes tracking a location or featureof the region of the anatomical structure in the image. Step S120preferably functions to track a location or feature of a region of theanatomical structure using a tracker and detector, such that the therapymodule may be notified of a change in location or feature of the targettissue. In some embodiments, step S120 occurs in response to a change inlocation or feature of the region of the anatomical structure.

As shown in FIG. 13, step S130 includes integrating the results from thetracking with the tracker and detector. Step S130 preferably functionsto determine if the results from the tracker and detector will be usedand if a new template should be generated based on the results from thetracker and detector. For example, if the tracking results from thetracker and detector, respectively, match a key template, as describedabove, the integrator will use the detector results and instruct thetherapy module to deliver therapy to the target tissue, such that aposition of the target tissue is known by the integrator and transmittedto the therapy module.

As shown in FIG. 13, step S140 includes generating a unique templatelibrary to cover possible changes of the one or more locations andfeatures of the region of the anatomical structure. Step S140 preferablyfunctions to maintain a template pool of possible locations and/orfeatures of the anatomical structure being tracked by the imagingmodule, such that the template pool was generated over time fromprevious images. Each result from the tracker and detector may becompared to the template pool to determine if 1) the result matches atemplate and thus the template can inform the therapy module as to theposition of the target tissue or 2) the result does not match a templateand a new template needs to be generated and thus the new template caninform the therapy module as to the position of the target tissue, asfurther recited in S150.

As shown in FIG. 13, step S160 includes delivering the therapy to thetarget tissue while tracking the region of the anatomical structure inthe image. Step S160 preferably functions to deliver therapy to thetarget tissue while consistently aligning an orientation, position, orotherwise direction of the therapy module with the target tissue. Thetherapy module, as described herein, receives information from theimaging module that pertains to a position of the target tissue, suchthat the tracker and detector track a position of the target tissue bytracking a region of an anatomical structure.

In some embodiments, the method of FIG. 13 further includessubstantially continuously delivering therapy to the target tissuedespite a change in one or more locations and features of the region ofthe anatomical structure. The therapy module may continue deliveringtherapy despite a change since the imaging module may alert, notify, orotherwise inform the therapy module of the change, and the therapymodule may adjust accordingly.

In some embodiments, the method of FIG. 13 further includes stopping theimaging of the region of the anatomical structure when the region of theanatomical structure is undetectable. For example, the anatomicalstructure may move perpendicularly away from the imaging plane, suchthat the region of the anatomical structure is undetectable. In someembodiments, the imaging module may automatically recover (e.g. withoutuser intervention) the region of the anatomical structure location orfeature, such that therapy delivery may resume. Further, automaticallyrecovering the region of the anatomical structure location or featuremay occur by first determining a last known location or feature of theregion of the anatomical structure in the image (logic function). Insome embodiments, the last known location or feature may correspond to atemplate from the template pool.

In some embodiments, the method of FIG. 13 further includes filteringthe image, such that the anatomical structure can be tracked in thefiltered image. The image may be filtered using a moving average filteror any other type of filter.

In some embodiments, the method of FIG. 13 further includes generating anew template when the pre-existing template does not match the trackingresults, such that the new template corresponds to a position of thetarget tissue in the image. In some embodiments, the new template isassigned as the key template, as described above. In some embodiments,the new template may be generated by the integrator.

In some embodiments, the method of FIG. 13 is implemented in a graphicsprocessing unit (GPU), FPGA, and/or DSP to further reduce thecomputation time of the tracker, detector and integrator.

As described herein, a method for treatment includes: acquiring with animaging module an image of a body portion of a patient; identifying aregion of an anatomical structure that has a relationship to a targettissue in the image; tracking a location and/or a feature of the regionof the anatomical structure in the image; transforming a target positionof the target tissue from an imaging space associated with the imagingmodule to a treatment space associated with a therapy module through oneor more position sensors and a transmitter; and delivering a therapywith the therapy module to the target tissue while tracking the regionof the anatomical structure. In some embodiments, the act oftransforming is performed to bring a target position of the targettissue (e.g., renal artery) in the imaging space (e.g., ultrasoundimaging coordinate) to a transformed target position in the treatmentspace (e.g., therapeutic array coordinate). Various techniques may beemployed to achieve such objective. For example, in some cases, areal-time electromagnetic tracking system with sub-millimeter andsub-degree accuracy may be used. The magnetic field sensor may beattached on the handle of the imaging transducer, and a magnetic fieldtransmitter may be attached to the base of therapeutic treatment module.The magnetic field transmitter generates a magnetic field. When themagnetic sensor is placed inside controlled, varying magnetic fieldsgenerated from the transmitter, voltage are induced in the sensor coils.These induced voltages can be used by the measurement system tocalculate the position and the orientation of the magnetic field sensorin 3D space. In such cases, after the renal artery target position isdetected by ultrasound imaging (in image coordinate), the transformationof the position may be performed as follows: 1) the treatment positionand orientation of a target in the image coordinate are linked with themagnetic field sensor position and orientation based on mechanicaldesign and calibration (in magnetic sensor coordinate); 2) the targetposition and orientation in the magnetic sensor coordinate are thentransformed into the treatment module coordinate by the detection of thesensor position and orientation in the magnetic field generated by themagnetic field transmitter, and 3) the target position and orientationin the treatment module coordinate are further transformed into thecoordinate of the therapeutic array. In some cases, the thirdtransformation above is not needed if the coordinate frame of thetherapeutic array is aligned with the treatment module coordinate frame.Therefore, knowing the position and orientation of the imaged targetrelative to the coordinate frame of the therapeutic array through theabove transformations, the therapeutic system can adjust the mechanicalmovement of the therapeutic array and/or the phases of the arrayelements to deliver the ultrasound energy at the imaged treatmenttarget.

In other embodiments, non-magnetic position measurement system may beused. This has the advantage of eliminating the possibilities of wrongtargeting when a metal object gets close to the magnetic sensor and thetransmitter. For example, in other embodiments, optical positionmeasurement system may be used that measures the 3D positions of eitheractive or passive markers affixed to application-specific tools. In oneimplementation, three different optical tool plates with at least threeoptical markers on each plate may be provided. One plate with opticalmarkers is attached with the handle of the imaging transducer. The othertwo plates are attached on the left and right sides of the therapeutictreatment module separately. An optical position sensor system may beattached to the base of therapeutic treatment module. The opticalposition sensor system emits infrared (IR) light from its illuminators,similar to the flash on a conventional camera. The emitted IR lightreflects back to the Position Sensor off markers (which may be sphericalor semi-spherical) on the passive tool plates. The optical positionsensor system then measures the positions of the markers and calculatesthe positions and orientations of the tool plates. The relationship ofboth positions and orientations between the tool plate attached to theimaging transducer (e.g., the handle) and the treatment module can bedetermined by the position sensor system at a rate of 20 Hz inreal-time. To further optimize the detection accuracy of the positionsand orientations between the imaging transducer and treatment module,the two plates which are attached along the left and right side of thetreatment module are orientated to the optimized angles for treating theright and left renal denervation separately. In such cases, after therenal artery target position is detected by ultrasound imaging (in imagecoordinate), the transformation of the positions and orientations of thetreatment target from the imaging coordinate to the therapy coordinatemay be performed as follows: 1) the target position and orientation inthe image coordinate are linked with the optical plate position (of theimaging transducer) based on mechanical design and calibration (toobtain treatment position and orientation in imaging tool platecoordinate); 2) the target position and orientation in the imaging toolplate coordinate are further transformed into optical position sensorcoordinate frame; 3) the target position and orientation in the positionsensor coordinate frame are then transformed into either left or righttool plate coordinate frame attached on the treatment module dependingon the treatment of right or left side renal nerves; 4) the targetposition and orientation in the left/right treatment tool platecoordinate frame are further transformed to the therapeutic arraycoordinate frame based on mechanical design dimension and calibrations.Thus, the therapeutic system may control the therapeutic array todeliver the ultrasound energy to the treatment target through the abovetransformations by adjusting the mechanical movement of the therapeuticarray and/or electronic phasing steering (e.g., in depth direction,and/or other direction(s)).

The systems and methods of the preferred embodiment and variationsthereof can be embodied and/or implemented at least in part as a machineconfigured to receive a computer-readable medium storingcomputer-readable instructions. The instructions are preferably executedby computer-executable components preferably integrated with the imagingmodule and/or the therapy module. The computer-readable medium can bestored on any suitable computer-readable media such as RAMs, ROMs, flashmemory, EEPROMs, optical devices (e.g., CD or DVD), hard drives, floppydrives, or any suitable device. The computer-executable component ispreferably a general or application-specific processor, for exampleVersatile Data Acquisition System (VDAS), but any suitable dedicatedhardware or hardware/firmware combination can alternatively oradditionally execute the instructions.

In other embodiments, instead of or in addition to using histogram(s), afeature matching technique such as Normalized Cross Correlation method,Sum Square Difference method, Sum Absolute Difference method, etc., maybe used.

The examples and illustrations included herein show, by way ofillustration and not of limitation, specific embodiments in which thesubject matter may be practiced. Other embodiments may be utilized andderived therefrom, such that structural and logical substitutions andchanges may be made without departing from the scope of this disclosure.Such embodiments of the inventive subject matter may be referred toherein individually or collectively by the term “invention” merely forconvenience and without intending to voluntarily limit the scope of thisapplication to any single invention or inventive concept, if more thanone is in fact disclosed. Thus, although specific embodiments have beenillustrated and described herein, any arrangement calculated to achievethe same purpose may be substituted for the specific embodiments shown.This disclosure is intended to cover any and all adaptations orvariations of various embodiments. Combinations of the aboveembodiments, and other embodiments not specifically described herein,will be apparent to those of skill in the art upon reviewing the abovedescription.

1-42. (canceled)
 43. A method for imaging during delivery of a therapy,the method comprising: acquiring an image of a body portion of apatient; identifying a region of an anatomical structure that has arelationship to a target tissue in the image; tracking a location and/ora feature of the region of the anatomical structure in the image;integrating results from the act of tracking; generating a templatelibrary to cover possible changes of the location and/or changes of thefeature of the region of the anatomical structure; and delivering thetherapy to the target tissue while tracking the region of the anatomicalstructure in the image.
 44. The method of claim 43, further comprisingcontinuously delivering therapy to the target tissue despite a change inone or more locations and features of the region of the anatomicalstructure.
 45. The method of claim 43, wherein the act of trackingoccurs in response to a change in the location or the feature of theregion of the anatomical structure.
 46. The method of claim 43, whereinthe region of the anatomical structure comprises the target tissue. 47.The method of claim 43, wherein at least one of breathing, blood flow,conscious movement, or unconscious movement of the patient changes thelocation and/or the feature of the region of the anatomical structure.48. The method of claim 43, wherein the region of the anatomicalstructure is undetectable by the imaging module as a result of at leastone of breathing, blood flow, conscious movement, and unconsciousmovement.
 49. The method of claim 48, further comprising stoppingimaging of the body portion of the patient when the region of theanatomical structure is undetectable.
 50. The method of claim 49,further comprising automatically re-detecting the region of theanatomical structure location or feature.
 51. The method of claim 50,wherein the automatically recovering step further comprisesautomatically recovering the region of the anatomical structure locationor feature by first determining a last known location or feature of theregion of the anatomical structure in the image.
 52. The method of claim43, wherein the act of tracking occurs in less than 5 milliseconds. 53.The method of claim 43, wherein the act of delivering the therapycomprises denervating renal nerves surrounding the renal artery.
 54. Themethod of claim 43, wherein the act of delivering comprises deliveringultrasound to the target tissue.
 55. The method of claim 43, wherein theact of tracking comprises using a B-mode image, Harmonic image, or 3DUltrasound imaging.
 56. The method of claim 43, wherein the act oftracking comprises using a color Doppler image, a color power Dopplerimage, or a directional color power Doppler mode image.
 57. The methodof claim 43, wherein the act of tracking comprises using an image inB-mode, Harmonic mode, color Doppler mode, color power Doppler mode, acombination of the B-mode, the Harmonic mode and the color Doppler mode.58. The method of claim 43, further comprising filtering the image toobtain a filtered image, such that the anatomical structure can betracked in the filtered image.
 59. The method of claim 43, furthercomprising determining if a pre-existing template matches a result fromthe act of tracking.
 60. The method of claim 43, further comprisingdetermining if a result from the act of tracking should be updated as anew template.
 61. The method of claim 59, wherein a position of thetarget tissue is based on the preexisting template and a new template.62. The method of claim 43, further comprising generating a new templatewhen a preexisting template does not match a result from the act oftracking, wherein the new template defines or indicates a location and ashape of the target tissue.
 63. A method for treatment comprising:acquiring with an imaging module an image of a body portion of apatient; identifying a region of an anatomical structure that has arelationship to a target tissue in the image; tracking a location and/ora feature of the region of the anatomical structure in the image;transforming a target position of the target tissue from an imagingspace associated with the imaging module to a treatment space associatedwith a therapy module through one or more position sensors and atransmitter and delivering a therapy with the therapy module to thetarget tissue while tracking the region of the anatomical structure. 64.The method of claim 63, wherein the one or more position sensors and thetransmitter are configured to link a position of an imaging transducerof the imaging module to a position of an ultrasound treatmenttransducer of the therapy module.
 65. The method of claim 63, whereinthe one or more position sensors comprises a magnetic sensor, an opticalsensor, an ultrasound sensor, or a mechanical position sensor.
 66. Themethod of claim 63, wherein the one or more position sensors are mountedon an imaging transducer of the imaging module.
 67. The method of claim63, wherein the transmitter is mounted on an imaging transducer of theimaging module.
 68. The method of claim 63, wherein the one or moreposition sensors are mounted on an ultrasound treatment transducer ofthe therapy module.
 69. The method of claim 63, wherein the transmitteris mounted on an ultrasound treatment transducer of the therapy module.70. The method of claim 43, wherein delivering the therapy to the targettissue comprises delivering ultrasound for drug delivery to the targettissue.
 71. The method of claim 63, wherein delivering the therapy withthe therapy module to the target tissue comprises delivering ultrasoundfor drug delivery to the target tissue.